Named for a river that in its upper reaches could pass for a creek, the Brandywine Valley stretches 35 miles from the rolling hills of southeastern Pennsylvania to the northern part of Wilmington, Delaware. And almost every acre is rich with romance, history, or just plain beauty.

1. Nemours Mansion
Go almost anywhere in Brandywine country, and you’re likely to encounter the name Du Pont. The first member of this notable clan to arrive in America, Pierre Samuel du Pont de Nemours, emigrated from France with his family in 1799. Three years later one of his sons, Eleuthére Irénée, established a gunpowder plant beside the Brandywine River in Delaware. By the early 20th century, the family business had grown into the world’s largest chemical company. The Du Ponts eventually became one of the richest families in America, and they poured a good deal of their wealth into their properties.

The first of several monuments to the Du Pont dynasty to be seen here is the Nemours Mansion, located on Rockland Road between Rtes. 202 and 141 north of Wilmington. A modified Louis XVI- style chateau, this 102-room masterpiece was built in 1910 by Pierre Du Pont’s great-grandson Alfred, who used it as a refuge from scorning relatives after his divorce. Antique furnishings, tapestries, and a fine collection of 17th-century Dutch paintings are among the items on exhibit here. Visitors to the 300-acre estate can cap a house tour with a stroll through gardens that some say rival those found at the Palace of Versailles.

2. Hagley Museum
Turning south on Rte. 141, the drive reaches the Hagley Museum, site of the Du Pont Company’s early gunpowder mills. In use from 1802 until 1921, when the mills closed, these works made the Du Pont family the largest manufacturer of gunpowder and construction explosives in America. Much of the original machinery has been carefully restored and can be toured in the Hagley Yards, part of the indoor-outdoor museum that traces the long history of powder making. Also found on these 240 wooded acres are several interesting buildings — including a furnished cottage and school — that vividly evoke the lifestyle of Du Pont workers and their families. Farther upstream, overlooking the original powder mills, sits Eleutherian Mills, an 1803 Georgian-style residence whose furnishings reflect the tastes of five generations of Du Ponts.

3. Winterthur
The rolling countryside near Centerville, Delaware, is a cornucopia of palatial estates. But no piece of real estate here can quite compare with Winterthur (pronounced WIN-ter-toor), the ancestral home of Henry Francis Du Pont. This 983-acre compound — which explodes with lyrically beautiful combinations of flowers from February until November-was lovingly landscaped by its owner, whose passion for his property led him to eventually become an expert in horticulture.

The magnificence of the grounds at Winterthur is perhaps exceeded only by that of its centerpiece, a nine-story museum housing some 90,000 examples of American decorative arts dating from 1640 to 1860. Installed in nearly 175 meticulously restored, period-accurate rooms, these rare objects — including silver tankards crafted by Paul Revere and a dinner service made for George Washington — form one of the largest treasuries of its kind in America.